Systems and Methods for Universal Imaging Components

ABSTRACT

A method of operating a cartridge chip installed in an imaging device includes: causing, by the cartridge chip, the imaging device to enter an error condition; monitoring the timing or sequence of communication signals received from the imaging device during at least a portion of the error condition; and operating, based on the timing or sequence of the communication signals received from the imaging device during at least a portion of the error condition, in a first mode of operation compatible with a first type of imaging device or in a second mode of operation compatible with a second type of imaging device.

BACKGROUND

The present invention generally relates to manufacturing orremanufacturing replaceable imaging components, and more particularly totechniques for providing a universal cartridge chip including a memoryelement adapted for use in multiple types of imaging cartridges.

In the imaging industry, there is a growing market for the remanufactureand refurbishing of various types of replaceable imaging cartridges suchas toner cartridges, drum cartridges, inkjet cartridges, and the like.Imaging cartridges, once spent, are unusable for their originallyintended purpose. Without a refurbishing process, they would simply bediscarded, even though the cartridge itself may still have potentiallife. As a result, techniques have been developed specifically toaddress this issue. These processes may entail, for example, thedisassembly of the various structures of the cartridge, replacing toneror ink, cleaning, adjusting or replacing any worn components andreassembling the cartridge.

Some imaging cartridges may include a cartridge chip having a memorydevice which is used to store data related to the cartridge or theimaging device. An imaging device may include laser printers, copiers,inkjet printers, facsimile machines and the like, for example. Theimaging device, such as the printer, reads the data stored in thecartridge memory device to determine certain printing parameters andcommunicates information to the user. For example, the memory may storethe model number of the imaging cartridge so that the printer mayrecognize the imaging cartridge as one which is compatible with thatparticular imaging device. Additionally, by way of example, thecartridge memory may store the number of pages that can be expected tobe printed from the imaging cartridge during a life cycle of the imagingcartridge and other useful data. The imaging device may also writecertain data to the memory device, such as an indication of the amountof toner remaining in the cartridge. Other data stored in the memorydevice may relate to the usage history of the toner cartridge.

Typically, each type of imaging cartridge requires a different type ofcartridge chip. While necessary to the proper operation of the imagingdevice, the differences between certain types of chip cartridges may besubtle or slight. With the ever increasing number of types and models ofimaging devices and imaging cartridges being sold, remanufacturers muststock an increasing number of types of cartridge chips, with each typeof cartridge chip usable with only a single type of imaging cartridge.It would be advantageous to provide systems and methods for a universalcartridge chip which operates with more than one type or model ofimaging cartridge, and thus in more than one type or model of printer.Additionally, it would be advantageous to provide systems and methodsfor a universal cartridge chip which allows one type of imagingcartridge to be used in multiple types of imaging devices. Furthermore,it would be advantageous to provide systems and methods for a universalcartridge chip that allows remanufacturers of imaging cartridges toreduce the number of types of cartridge chips stored in their inventory.

SUMMARY

In one aspect of the present invention a method of operating a cartridgechip installed in an imaging device includes: causing, by the cartridgechip, the imaging device to enter an error condition; monitoring thetiming or sequence of communication signals received from the imagingdevice during at least a portion of the error condition; and operating,based on the timing or sequence of the communication signals receivedfrom the imaging device during at least a portion of the errorcondition, in a first mode of operation compatible with a first type ofimaging device or in a second mode of operation compatible with a secondtype of imaging device.

In another aspect of the present invention a method of operating acartridge chip installed in an imaging device includes: causing, by thecartridge chip, the imaging device to enter an error condition;monitoring the timing or sequence of communication signals received fromthe imaging device during at least a portion of the error condition; anddetermining, based on the timing of the communication signals receivedfrom the imaging device, if the imaging device is a first type ofimaging device or a second type of imaging device; operating thecartridge chip in a first mode of operation if the imaging device isdetermined to be the first type of imaging device; and operating thecartridge chip in the second mode of operation if the imaging device isdetermined to be the second type of imaging device.

In another aspect of the present invention, a cartridge chip for usewith an imaging cartridge installed in an imaging device includes: amemory element storing imaging cartridge data; and a controller forcontrolling the operation of the cartridge chip, causing the imagingdevice to enter an error condition, monitoring the timing or sequence ofcommunication signals received from the imaging device during at least aportion of the error condition, and operating, based on the timing orsequence of the communication signals received from the imaging device,in a first mode of operation compatible with a first type of imagingdevice or in a second mode of operation compatible with a second type ofimaging device.

In another aspect of the present invention, a cartridge chip for usewith an imaging cartridge installed in an imaging device includes: amemory element storing imaging cartridge data; and a controller forcontrolling the operation of the cartridge chip, causing the imagingdevice to enter an error condition, determining, based on the timing orsequence of the communication signals received from the imaging device,if the imaging device is a first type of imaging device or a second typeof imaging device, operating the cartridge chip in a first mode ofoperation if the imaging device is determined to be the first type ofimaging device, and operating the cartridge chip in the second mode ofoperation if the imaging device is determined to be the second type ofimaging device.

These and other features and objects of the invention will be more fullyunderstood from the following detailed description of the embodiments,which should be read in light of the accompanying drawings.

In this regard, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the description orillustrated in the drawings. The invention is capable of otherembodiments and of being practiced and carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein, as well as the abstract, are for the purpose ofdescription and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be used as a basis fordesigning other structures, methods, and systems for carrying out theseveral purposes of the present invention. It is important, therefore,that the claims be regarded as including such equivalent constructionsinsofar as they do not depart from the spirit and scope of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate embodiments of the present invention and,together with the description, serve to explain the principles of theinvention;

FIG. 1 shows a functional block diagram of a universal chip inaccordance with the present invention;

FIG. 2 shows a perspective view of a universal chip in accordance withthe present invention;

FIG. 3 shows a perspective view of a universal chip installed on animaging cartridge in accordance with the present invention; and

FIGS. 4 and 5 show timing diagrams in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

The following detailed description of preferred embodiments refers tothe accompanying drawings which illustrate specific embodiments of theinvention. In the discussion that follows, specific systems andtechniques for repairing, manufacturing or remanufacturing a tonercartridge comprising a cartridge chip including a memory element aredisclosed. Other embodiments having different structures and operationsfor the repair, remanufacture and operation of other types ofreplaceable imaging components and for various types of imaging devices,such as laser printers, inkjet printers, copiers, facsimile machines andthe like, do not depart from the scope of the present invention.

FIG. 1 shows a functional block diagram of a universal chip 100 inaccordance with the present invention. The universal chip 100 maysuitably include input and output (I/O) interface circuitry 102, acontroller 104, and a memory 106. The I/O interface circuitry 102 iscommunicatively connected to the controller 104 and provides theappropriate electronic circuitry for the controller 104 to communicatewith an imaging device, such as a printer. As an example, for imagingdevices which communicate utilizing radio frequency (RF), the I/Ointerface circuitry 102 may include a radio frequency (RF) antenna andcircuitry, and for a direct wired connection to imaging devices the I/Ointerface circuitry 102 may include one or more contact pads, or thelike, and interface circuitry.

As described in greater detail below, the controller 104 controls theoperation of the universal chip 100 and provides a functional interfaceto the memory 106, including controlling the reading of data from andthe writing of data to the memory 106 by the printer. The data read fromor written to the universal cartridge chip 100 may include a printertype, cartridge serial number, the number of revolutions performed bythe organic photo conductor (OPC) drum (drum count), the manufacturingdate, number of pages printed (page count), percentage of tonerremaining, yield (expected number of pages), color indicator, toner-outindicator, toner low indicator, virgin cartridge indicator (whether ornot the cartridge has been remanufactured before), job count (number ofpages printed and page type), and any other data or program instructionsthat may be stored on the memory 106.

The controller 104 may be suitably implemented as a custom orsemi-custom integrated circuit, a programmable gate array, amicroprocessor executing instructions from the memory 106 or othermemory, a microcontroller, or the like. Additionally, the controller104, the memory 106 and/or the I/O interface circuitry 102 may beseparated or combined in one or more physical modules. These modules maybe suitably mounted to a printed circuit board to form the universalcartridge chip 100. FIG. 2 shows a perspective view of one embodiment ofthe universal cartridge chip 100 in accordance with the presentinvention. FIG. 3 shows a perspective view of another embodiment of theuniversal cartridge chip 100 installed on an exemplary imaging cartridge300 in accordance with the present invention.

Different printer types may communicate or interface with in differentways with the cartridge chips installed on toner cartridges. Differentprinter types may include printers that differ by model number, firmwareversion, region of operation and other differences. These differentprinter types may expect differing data to be stored in the cartridgechip or utilize the stored data in different ways. When installed in orattached to an imaging cartridge which is installed in an imagingdevice, the universal chip 100 of the present invention causes theprinter to enter an error condition by not responding to a commandtransmitted by the printer or by responding incorrectly to the commandtransmitted by the printer. The error condition may be repeated a numberof times to generate a statistically significant sample set of timingvalues associated with each of the error conditions. The repeated errorconditions provide a stable and repeatable environment to detectdiffering timing characteristics exhibited by different printer types.Additionally, during the error condition the universal chip 100 maydetect differences in the error sequence generated by differentprinters.

Based at least partially on the sample set of the timings or thesequence of communication signals received from the imaging deviceduring the error conditions, the universal cartridge chip 100 may thenoperate in a first mode of operation compatible with a first type ofimaging device or a second mode of operation compatible with a secondtype of imaging device. The first mode of operation may differ from thesecond mode of operation in at least one attribute, such as datacontent, communication type, and timing, for example. Additionally, theuniversal chip 100 may determine if the imaging device is the first typeof imaging device or the second type of imaging device. If the universalchip 100 determines that the imaging device is the first type of imagingdevice, the universal chip 100 operates in a first mode of operationcompatible with the first type of imaging device. If the universal chip100 determines that the imaging device is the second type of imagingdevice, the universal cartridge chip operates in a second mode ofoperation compatible with the second type of imaging device.

As an example, FIG. 4 shows a timing diagram 400 of communicationsignals transmitted by a first and a second printer type when acartridge comprising the chip 100 is installed in the printer. After apower-on reset (POR) signal 402 is asserted, a clock signal 404 istransmitted to the chip 100. The printer then transmits a validationcommand 406 followed by a read command 408 to the chip 100. If the chip100 does not respond to either command, then the printer may enter anerror state and toggle POR reset and repeat the sequence multiple times,as shown in FIG. 5. The sequence of the signals transmitted by the firstand second printer types may be substantially the same, but differslightly in timing. Alternatively, the sequence of the signalstransmitted may be different. For example, the time elapsed T1 from thefirst clock signal 404 until the validation command 406 may differbetween the two printer types across a range of values. The time elapsedT1 for the first printer type may vary within a range of 1000 to 1200clock cycles and the time elapsed for the second printer type may varywithin a range of 1300 to 1500 clock cycles. These printer timing rangesare predetermined and stored in the memory 106. By counting the clockcycles between the first clock signal 404 and the validation command 406to determine the time elapsed T1, the universal chip 100 may determinewhich range the clock signals fall within and then determine the printertype. By not responding to the validation command 406 and the readcommand 408 multiple times during the error condition, the universalchip 100 may acquire multiple data samples of the elapsed time T1 anddetermine a minimum time which is compared with the predetermined rangesstored in the universal chip 100 to determine the printer type. Forexample, if the minimum time elapsed T1 is 1050 clock cycles, theprinter will be determined to be the first printer type. If the minimumtime does not match either range and the chip 100 does not respond orotherwise operates in a mode of operation not compatible with theprinter, the printer will be eventually forced into a terminal errorcondition requiring the end user to re-install the cartridge or open andclose the cartridge access door to reset the timing detect circuitry ofthe controller 104. The process would them be repeated until the minimumtime is determined that falls within one of the predetermined ranges.

Based on the determination of the printer type, the universal chip 100will interoperate with the printer in a particular mode of operationcompatible with that printer. For example, if the universal chip 100determines the printer is an HP 1515, the universal chip 100 may presenta memory map to the printer when the printer reads from the memory 106.If the universal chip 100 determines the printer is an HP 1525, theuniversal chip 100 may present a different memory map when the printerreads from the memory 106. FIG. 5 shows a timing diagram of acommunication sequence including multiple validation commands and readcommands. After the universal chip 100 has determined the printer type,it responds appropriately to the validation and read commands with aresponse 502 based on the determined printer type.

While in a preferred embodiment, the universal chip 100 may record thetime elapsed T1 from the first clock signal 404 until the validationcommand 406 in order to determine the printer type, other elapsed timesbetween other events or signals may also be used. For example, theuniversal chip may respond correctly to the validation command but notrespond to succeeding reads. The timing of these reads may be used todetermine printer type.

Additionally, instead of causing the error condition by not respondingto a signal transmitted from the printer, the universal chip 100 maycause the error condition by responding incorrectly to the signal.

Color imaging devices may include multiple cartridges, with eachcartridge holding a different color marking material. Each of the colorcartridges is installed in a separate slot in the imaging device.Different slots of a printer type may communicate or interface with indifferent ways with the cartridge chips installed on imaging cartridgesinstalled in those slots. Many color imaging devices use four differentcolor marking materials: cyan, magenta, yellow, and black. Some colorimaging devices use seven colors: cyan light, cyan dark, magenta light,magenta dark, yellow light, yellow dark, and black. Some photographicquality imaging devices use more colors while some imaging devices use acolor free material to help the quality of the printed image. Also, somecolor imaging devices use only two cartridges, a black cartridge and amulticolor cartridge that has three or more separate colors containedtherein.

In an alternate embodiment of the present invention, the universal chip100 attached to a color imaging cartridge installed in one of the colorslots of an imaging device may cause the imaging device to enter anerror condition and monitor the timing or sequence of communicationsignals received from the imaging device during at least a portion ofthe error condition. The universal chip 100 may then, based on thetiming or sequence of the communication signals received from theimaging device during at least a portion of the error condition, operatein a first mode of operation compatible with a first cartridgecontaining a first color recording material or in a second mode ofoperation compatible with a second cartridge containing a second colorrecording material. The first color and the second color are differentcolors. Additionally, one of the cartridges may contain multiple colorsor a color free material. Additionally, as described above, the mode ofoperation may be compatible with a first type of imaging device or asecond type of imaging device.

The universal chip 100 may determine, based on the timing or sequence ofthe communication signals received from the imaging device, if a slotthe cartridge chip is installed in is for the first color recordingmaterial or if the slot the cartridge chip is installed in is for thesecond color recording material. The cartridge chip will operate in thefirst mode of operation if the slot the cartridge chip is installed inis determined to be the slot for the first color recording material, andoperating the cartridge chip in the second mode of operation if the slotthe cartridge chip is installed in is determined to be the slot for thesecond color recording material.

Each cartridge chip includes a unique identifier, such as a serialnumber, which is read by the imaging device when the cartridge isinstalled in the imaging device. Some imaging devices include a “blacklist” of banned unique identifiers with which the imaging device willnot operate. In one embodiment, the universal chip 100 may cause theimaging device to enter an error condition and, based on the timing orsequences signals received from the imaging device, determine if theprinter includes a “black list.” If the imaging device does not includea “black list,” the universal cartridge chip 100 will operate in a modeof operation compatible with that imaging device. If the printer doesinclude a “black list,” the universal chip 100 will communicateadditional unique identifiers stored in its memory to the imaging devicein order to determine a unique identifier that is acceptable to theimaging device and then operate in mode of operation that is compatiblewith that imaging device.

In another embodiment, the universal chip 100 may cause the imagingdevice to enter an error condition when the unique identifier is notcompatible with the imaging device. During the error condition, the chipchanges the unique identifier communicated to the imaging device withoutperforming the detection described above. This enables the universalchip 100 to operate in an imaging device that uses a blacklist withoutdetecting that the printer is a blacklisted printer.

In another embodiment, the memory 106 of the universal chip 100 includesan area for storing multiple identifiers. The area of the memory that isused to store identifiers is filled with data that does not representvalid identifiers. After authentication, the imaging device reads asection of the memory 106 where the identifiers are stored. If data isstored in this location, the imaging device updates the blacklist withthe data. In this embodiment, the imaging device updates the blacklistwith the data that is stored instead of valid unique identifiers. Thisfills the blacklist with data preventing new unique identifiers frombeing loaded into the blacklist from this point on.

Although the unique identifier is described as serial number, any uniqueidentifier that can be represented by data is suitable. For example, theunique identifier could be a partial serial number, a manufacture date,a manufacturer identification, or any other desired data or code.

Alternately, multiple sequences of different error condition types maybe used to determine the printer type.

In an alternate embodiment, the universal chip 100 may respond correctlyto the validation command and then either not respond or respondincorrectly to a following read command.

In another aspect of the present invention, the universal chip 100 mayrespond incorrectly or not respond to a validation command transmittedfrom the printer in order to cause the printer to enter an errorcondition. This may be repeated a plurality of times with the universalchip 100 monitoring the timing or sequence of the communication signals.Next, before the printer reaches a threshold value for the maximumnumber of validation retry attempts, the universal chip 100 may respondcorrectly to a validation signal and then respond incorrectly or notrespond to a succeeding read command. Thus, the universal chip 100 mayacquire timing or sequence data over two types of cascading errorconditions.

The many features and advantages of the invention are apparent from thedetailed specification. Thus, the appended claims are intended to coverall such features and advantages of the invention which fall within thetrue spirits and scope of the invention. Further, since numerousmodifications and variations will readily occur to those skilled in theart, it is not desired to limit the invention to the exact constructionand operation illustrated and described. Accordingly, all appropriatemodifications and equivalents may be included within the scope of theinvention.

Although this invention has been illustrated by reference to specificembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made which clearly fall withinthe scope of the invention. The invention is intended to be protectedbroadly within the spirit and scope of the appended claims.

What is claimed is:
 1. A method of operating a cartridge chip installedin an imaging device comprising: causing, by the cartridge chip, theimaging device to enter an error condition; monitoring the timing orsequence of communication signals received from the imaging deviceduring at least a portion of the error condition; and operating, basedon the timing or sequence of the communication signals received from theimaging device during at least a portion of the error condition, in afirst mode of operation compatible with a first type of imaging deviceor in a second mode of operation compatible with a second type ofimaging device, the first mode of operation differing from the secondmode of operation.
 2. The method of claim 1 further comprising:determining, based on the timing or sequence of the communicationsignals received from the imaging device, if the imaging device is thefirst type of imaging device or the second type of imaging device,operating the cartridge chip in the first mode of operation if theimaging device is determined to be the first type of imaging device, andoperating the cartridge chip in the second mode of operation if theimaging device is determined to be the second type of imaging device. 3.The method of claim 1 wherein causing the imaging device to enter anerror condition comprises: failing to respond to a signal transmitted bythe imaging device.
 4. The method of claim 1 wherein causing the imagingdevice to enter the error condition comprises: responding incorrectly toa signal transmitted by the imaging device.
 5. The method of claim 1wherein monitoring the timing of communication signals comprises:counting a number of clock signals between two events.
 6. The method ofclaim 5 wherein the step of counting a number of clock signals isrepeated a plurality of times.
 7. The method of claim 2 whereindetermining further comprises: comparing the timing of the communicationsignals to a plurality of timing ranges stored in a memory.
 8. Themethod of claim 1 wherein the first mode of operation is compatible withthe first type of imaging device not having a list of banned serialnumbers and the second mode of operation is compatible with second typeof device having a list of banned serial numbers.
 9. The method of claim8 wherein the second mode of operation comprises: transmitting, by thecartridge chip, a plurality of serial numbers to the imaging device todetermine a serial that is not included in the list of banned serialnumbers.
 10. The method of claim 1 wherein causing the imaging device toenter an error condition further comprises: responding correctly to avalidation command transmitted by the imaging device; and respondingincorrectly to a read command transmitted by the imaging device.
 11. Themethod of claim 1 wherein causing the imaging device to enter an errorcondition further comprises: responding correctly to a validationcommand transmitted by the imaging device; and not responding to a readcommand transmitted by the imaging device.
 12. The method of claim 1wherein causing the imaging device to enter an error condition furthercomprises: responding incorrectly to a first type of command a pluralityof times; responding correctly to the first type of command; andresponding incorrectly to a second type of command a plurality of times.13. The method of claim 12 wherein the first type of command is avalidation command and the second type of command is a read command. 14.A cartridge chip for use with an imaging cartridge installed in animaging device, the cartridge chip comprising: a memory element storingimaging cartridge data; and a controller for controlling the operationof the cartridge chip, causing the imaging device to enter an errorcondition, monitoring the timing or sequence of communication signalsreceived from the imaging device during at least a portion of the errorcondition, and operating, based on the timing or sequence of thecommunication signals received from the imaging device, in a first modeof operation compatible with a first type of imaging device or in asecond mode of operation compatible with a second type of imagingdevice, the first mode of operation differing from the second mode ofoperation.
 15. The cartridge chip of claim 14 wherein the controller isfor: determining, based on the timing of the communication signalsreceived from the imaging device, if the imaging device is the firsttype of imaging device or the second type of imaging device, operatingthe cartridge chip in the first mode of operation if the imaging deviceis determined to be the first type of imaging device, and operating thecartridge chip in the second mode of operation if the imaging device isdetermined to be the second type of imaging device.
 16. The cartridgechip of claim 14 wherein the controller is for: causing the imagingdevice to enter an error condition by failing to respond to a signaltransmitted by the imaging device.
 17. The cartridge chip of claim 14wherein the controller is for: causing the imaging device to enter theerror condition comprises by responding incorrectly to a signaltransmitted by the imaging device.
 18. The cartridge chip of claim 14wherein the controller is for: monitoring the timing of communicationsignals by counting a number of clock signals between two events. 19.The cartridge chip of claim 18 wherein the controller is for countingthe number of clock signals a plurality of times.
 20. The cartridge chipof claim 15 wherein the controller is for: comparing the timing of thecommunication signals to a plurality of timing ranges stored in amemory.
 21. The cartridge chip of claim 14 wherein: the first mode ofoperation is compatible with the first type of imaging device not havinga list of banned serial numbers and the second mode of operation iscompatible with second type of device having a list of banned serialnumbers.
 22. The cartridge chip of claim 21 wherein during the secondmode of operation the controller is for: transmitting, by the cartridgechip, a plurality of serial numbers to the imaging device to determine aserial that is not included in the list of banned serial numbers
 23. Thecartridge chip of claim 14 wherein the controller is for: respondingcorrectly to a validation command transmitted by the imaging device; andresponding incorrectly to a read command transmitted by the imagingdevice.
 24. The cartridge chip of claim 14 wherein the controller isfor: responding correctly to a validation command transmitted by theimaging device; and not responding to a read command transmitted by theimaging device.
 25. The cartridge chip of claim 14 wherein thecontroller is for: responding incorrectly to a first type of command aplurality of times; responding correctly to the first type of command;and responding incorrectly to a second type of command a plurality oftimes.
 26. The cartridge chip of claim 25 wherein the first type ofcommand is a validation command and the second type of command is a readcommand.
 27. A method of operating a cartridge chip installed in animaging device comprising: causing, by the cartridge chip, the imagingdevice to enter an error condition; monitoring the timing or sequence ofcommunication signals received from the imaging device during at least aportion of the error condition; and operating, based on the timing orsequence of the communication signals received from the imaging deviceduring at least a portion of the error condition, in a first mode ofoperation compatible with a cartridge having a first color recordingmaterial or in a second mode of operation compatible with a cartridgehaving a second color recording material, wherein the first color andthe second color are different.
 28. The method of claim 27 wherein thecontroller is for: determining, based on the timing or sequence of thecommunication signals received from the imaging device, if a slot thecartridge chip is installed in is for the first color recording materialor if the slot the cartridge chip is installed in is for the secondcolor recording material, operating the cartridge chip in the first modeof operation if the slot the cartridge chip is installed in isdetermined to be the slot for the first color recording material, andoperating the cartridge chip in the second mode of operation if the slotthe cartridge chip is installed in is determined to be the slot for thesecond color recording material.
 29. The method of claim 27 whereincausing the imaging device to enter an error condition comprises:failing to respond to a signal transmitted by the imaging device. 30.The method of claim 27 wherein causing the imaging device to enter theerror condition comprises: responding incorrectly to a signaltransmitted by the imaging device.
 31. The method of claim 27 whereinmonitoring the timing of communication signals comprises: counting anumber of clock signals between two events.
 32. The method of claim 31wherein the step of counting a number of clock signals is repeated aplurality of times.
 33. The method of claim 28 wherein determiningfurther comprises: comparing the timing of the communication signals toa plurality of timing ranges stored in a memory.
 34. The method of claim27 wherein causing the imaging device to enter an error conditionfurther comprises: responding correctly to a validation commandtransmitted by the imaging device; and responding incorrectly to a readcommand transmitted by the imaging device.
 35. The method of claim 27wherein causing the imaging device to enter an error condition furthercomprises: responding correctly to a validation command transmitted bythe imaging device; and not responding to a read command transmitted bythe imaging device.
 36. The method of claim 27 wherein causing theimaging device to enter an error condition further comprises: respondingincorrectly to a first type of command a plurality of times; respondingcorrectly to the first type of command; and responding incorrectly to asecond type of command a plurality of times.
 37. The method of claim 36wherein the first type of command is a validation command and the secondtype of command is a read command.
 38. The method of claim 27 whereinthe second cartridge contains three or more color recording materialstherein.
 39. The method of claim 27 wherein the second color is clear orcolor free.